Next, we examined the association between anhedonia and childhood physical abuse, stratified by genotype (coded AA/AG or GG). In GG individuals, there was a highly significant association between anhedonia and abuse [O.R. 5.09, 95% C.I. 2.66–9.77]. As shown in Table 2, 57.1% of GG individuals with a history of childhood physical abuse reported anhedonia compared with 20.7% of non-abuse GG individuals (also Figure 1). In contrast, in AA/AG individuals, there was no significant association between anhedonia and abuse [O.R. 1.66, 95% C.I. 0.89–3.09] with 28.6% and 19.4% of abused and non-abused subjects reporting anhedonia respectively. We also examined all three genotype groups separately (GG, AG, AA). However, given the small number of AA individuals exposed to abuse, estimates for AA and AG genotypes could be statistically equated, allowing us to combine AA and AG groups.
